<p><?php echo $this->getTranslation('Select the template for this page')?> ...</p><?php

$contentForm = new Admin_Form_Page();
$templateControl = $contentForm->getElement('content_template');
$currentTemplate = !empty($this->page->page->content_template) ? $this->page->page->content_template : null;
$templateControl->setValue($currentTemplate);

$form = new Core_Form();

$hidden = $form->createElement('hidden', 'id', array(
    'value' => $this->pageId,
));

$submit = $form->createElement('submit', 'updateContentTemplate', array(
    'label' => $this->getTranslation('Update Content Template'),
));

$form->addElement($hidden)
     ->addElement($templateControl)
     ->addElement($submit);

$form->setAction($this->getBaseUrl() . '/admin/page/update-template')
     ->addDisplayGroup(
         array('form_instance', 'id', 'content_template', 'updateContentTemplate'),
         'pageTemplateGroup',
         array('legend' => 'Content Template')
     );
echo $form;